Serum angiotensin converting enzyme elevation in association with artificial stone silicosis.

BACKGROUND: Silicosis is a rapidly emerging major health concern for workers in the artificial stone benchtop industry. The association between serum angiotensin converting enzyme (sACE) levels and artificial stone silicosis is unknown. METHODS: We investigated 179 male workers (median age 40 years, interquartile range (IQR) 33-48 years) from the stone benchtop industry in Victoria, Australia. All had worked in an environment where dry processing of artificial stone had occurred and were registered with the Victorian Silica-associated Disease Registry between June 2019 and August 2020. Workers had undergone protocolised assessments including respiratory function testing, high resolution CT chest and blood tests panel, including sACE. FINDINGS: Sixty workers with artificial stone silicosis were identified and they had a higher median sACE level (64.1 U/L, IQR 51.5, 87.5), compared to 119 without silicosis (35.0 U/L, IQR 25.0, 47.0). Compared to those with a normal assessment, regression modelling noted significantly higher average differences in sACE levels for workers with lymphadenopathy alone (12.1 U/L, 95% confidence interval (CI): 1.3, 22.9), simple silicosis (28.7 U/L, 95% CI: 21.3, 36.0) and complicated silicosis (36.0 U/L, 95% CI 25.2, 46.9). There was a small negative association with gas transfer, but no associations with exposure duration or spirometry. CONCLUSION: sACE levels were noted to be higher in artificial stone workers with silicosis compared to those without disease and was highest in those with complicated silicosis. Longitudinal follow up is required to evaluate sACE as a prognostic biomarker for workers with this rapidly emerging occupational lung disease.

Work-associated irritable larynx syndrome.

BACKGROUND: Work-associated respiratory symptoms may be caused by disorders of both the lower and upper respiratory tract. We propose that occupational exposures may initiate and/or trigger recurrent hyperkinetic laryngeal symptoms, predominantly episodic dyspnoea, dysphonia, cough and sensation of tension in the throat-work-associated irritable larynx syndrome (WILS). AIMS: To examine characteristics of individual and work-related factors that are associated with WILS, occupational asthma (OA) and work-exacerbated asthma (WEA). METHODS: Subjects with WILS, OA and WEA were identified from an occupational lung disease clinic. A review of 448 charts of patients attending the clinic between 2002 and 2006 was undertaken, with information entered onto a standardized abstraction form. RESULTS: Fifty subjects were identified with OA, 40 with WEA and 30 with WILS. Subjects with the diagnosis of WILS were more likely to be female and more frequently reported symptoms of gastro-oesophageal reflux. The most common triggers of workplace symptoms in the WILS group were odours, fumes, perfumes and cleaning agents. Fourteen patients with WILS identified a specific precipitating event at the workplace at the time of the onset of their symptoms and five of these subjects presented to an emergency department within 24 h of the event. CONCLUSIONS: Dysfunction of the upper airway is an important cause of work-associated respiratory symptoms. The identification and management of WILS requires a multidisciplinary approach with a focus on modifying work-related and intrinsic factors that may perpetuate symptoms.